Two-way circuit arrangement for wireless telephony



Nov. 22, 1927.

1,650,250 0. VON BRONK TWO-WAY CIRCUIT ARRANGEMENT FOR WIRELESS TELEPHONY Filed Feb. 20. 1923 gave whoa DTTO VON BRONK w ga 64/ [(4% Patented Nov. 22, @927.

UNITED STATES PATENT OFFICE.

OTTO VON BRONK, OF BERLIN, GERMANY, ASSIGNOR TO GESELLSCHAFT EUR DRAHT- LOSE TELEGRAPHIE M. B. H. HALLESCHES, OF BERLIN, GERMANY, A CORPORATION or GERMANY.

TWO-WAY CIRCUIT ARRANGEMENT FOR WIRELESS TELEPHONY.

Application filed February 20, 1923, Serial No 620,222, and in Germany September 9, 1921.

This two-fold operation is made possible by providin the cathode tube in a regenerative circuit w ich is adapted to generate oscillations during sending. In order to make it possible to use the circuit for communication in both directions in wireless telephony,

the telephone receiver and transmitter are connected in series in the anode circuit. The back coupling is weakened to an extent necessary for eliminating the generation of undesirable noises. It has been" suggested to use a single tube for both receiving and sending purposes in wireless telegraphy and telephony; however, nobody has as yet succeeded in providing a satisfactory circuit arrangement therefor.

In the drawings a circuit arrangement for two-way connections is illustrated for the purpose of exemplifying the invention.

1 is the antenna which is connected with ground 4 through the self induction 2 or condenser 3 and the block condenser 7 The oscillating circuit composed of the condenser 3 and the self induction 2 is connected on the one hand at point 8 through the grid circuit condenser 12 with the grid 11 of the tube 10 and on the other hand at point 9 through the variable coil 18 with the anode 16. The antenna circuit is connected at point 13 with the cathode 17 of the tube 10.

Furthermore, the grid 11 is connected in the well known manner through a grid leak resistance 15 with the cathode 17 in order to limit the negative charging of the grid. The iron resistance 14 may be provided in the 4 cathode circuit for ballast as is well understood. In addition to coil 18, the anode circuit of the tube 10 comprises also the telephone transmitter 19 and the block condenser 20 with which the telephone receiver 21 is connected in parallel.

The operation of the circuit arrangement is as follows:

The oscillations received by the antenna 1 are conducted to the grid circuit of the tube and may be heard in receiver 21 which is located in the anode circuit of the tube. IVhen the telephone transmitter 19 is actuated by speech thus causing the lowering of the resistance of the anode circuit and thereby allowing more energy to be fed back across the coupling comprising coils 2 and 18, oscillations are produced in the well known manner which are then radiated through the antenna. In case heavier current is used, the telephone transmitter instead of being connected directly with the circuit, will be connected in the well known manner b inductive coupling or other economical circuit arrangement with the anode circuit.

Having described my invention I declare that what I claim is- 1. Two way system for radio communication comprising a thermionic valve, a combined sending and receiving circuit said valve having its output and input clrcuits conductively and regeneratively coupled by means of said sending and receiving circuit, said output circuit comprising transmitting means and receiving means connected in series circuit.

2. Two way system for radio communication comprismg an oscillatory circuit consisting of an inductance and capacitance in parallel, a second capacitance connected to said oscillatory circuit and a combined sending and receiving circuit in series with said oscillatory circuit, a thermionic valve, the grid circuit of said valve being connected across said oscillatory circuit and second capacitance, and the plate circuit connected across said second capacitance, transmitting means and receiving means in series also connected across said second capacitance.

3. Two way system for radio communication comprising a thermionic valve having its grid and plate circuits regeneratively coupled, a combined sending and-receiving circuit operatively connected to said circuits, a grid condenser in said grid circuit, said plate circuit having therein transmitting means and receiving means in series.

4. A two way radio communication sys-' tem comprising a transmission conductor vice, means for loosely coupling said anode for receiving or transmitting, an oscillatory circuit to said oscillatory circuit and further circuit connected therewith, a three element means for couplin said anode circuit to the tube having its grid circuit connected across transmission con uctor for transmitting 5 said oscillatory circuit for receiving signals signals.

and its anode circuit including a signal responsive device and a signal initiating de- OTTO VQN BRONK. 

